vitamin b6 Overview Information

Pyridoxine is a vitamin. It can be found in certain foods such as cereals, beans, vegetables, liver, meat, and eggs. It can also be made in a laboratory.

Pyridoxine is used for preventing and treating low levels of pyridoxine (pyridoxine deficiency) and the “tired blood” (anemia) that may result. It is also used for heart disease; high cholesterol; reducing blood levels of homocysteine, a chemical that might be linked to heart disease; and helping clogged arteries stay open after a balloon procedure to unblock them (angioplasty).

Pyridoxine is frequently used in combination with other B vitamins in vitamin B complex products.

You may remember a prescription medication called Bendectin that was used for morning sickness in pregnancy. Bendectin contained pyridoxine and a sleep-inducing antihistamine called doxylamine. The makers of Bendectin took it off the market in 1983 because they were running up expensive legal bills in defense of their product. Opponents charged it might be responsible for birth defects. Meanwhile, a product called Diclectin that is similar to Bendectin remained available in Canada, and there was research showing that neither pyridoxine nor Bendectin seems to cause birth defects in animals. After Bendectin was removed from the market, there was no reduction in birth defects, but hospitalization rates for pregnancy-related nausea and vomiting doubled.

How does it work?

Pyridoxine is required for the proper function of sugars, fats, and proteins in the body. It is also required for the proper growth and development of the brain, nerves, skin, and many other parts of the body.

Macular degeneration. Some research shows that taking pyridoxine with other vitamins including folic acid and vitamin B12 might help prevent the loss of vision caused by the eye disease called age-related macular degeneration.

Behavior disorder in children caused by low serotonin levels (hyperkinetic cerebral dysfunction syndrome). Early research shows that taking pyridoxine by mouth might have a beneficial effect on children with a behavior disorder caused by low serotonin levels.

High blood pressure. Early research suggests that taking pyridoxine can lower blood pressure in people with high blood pressure

Kidney stones. There is some evidence that taking pyridoxine alone or combined with magnesium can decrease the risk of kidney stones in people with a hereditary disorder that increases their risk of forming kidney stones (type I primary hyperoxaluria). However, it does not appear to help people with other kinds of kidney stones.

Lung cancer. Taking pyridoxine by mouth seems to decrease the risk of lung cancer in individuals who smoke.

Upset stomach and vomiting in pregnancy. Some research suggests pyridoxine does not improve symptoms of mild to moderate nausea as much as severe nausea. The American College of Obstetrics and Gynecology considers pyridoxine a first-line treatment for nausea and vomiting caused by pregnancy. Pyridoxine plus the medication doxylamine is recommended for women who do not get better when treated with just pyridoxine.

Premenstrual syndrome (PMS). There is some evidence that taking pyridoxine by mouth can improve PMS symptoms including breast pain. The lowest effective dose should be used. Higher doses will increase the chance of side effects and are not likely to increase the beneficial effects.

Alzheimer's disease. Some evidence suggests that taking pyridoxine supplements does not reduce the risk of Alzheimer’s disease in older people.

Itchy and inflamed skin (atopic eczema). Early research suggests that taking pyridoxine daily for 4 weeks does not reduce eczema symptoms in children.

Autism. Taking pyridoxine with magnesium daily does not seem to improve autistic behavior in children.

Carpal tunnel syndrome. Although some early research suggests that pyridoxine might relieve certain symptoms of carpal tunnel syndrome, most research suggests that this supplement does not benefit people with this condition.

Mental function. Taking pyridoxine daily together with folic acid and vitamin B12 does not seem to improve mental function in older people.

Stopping breast milk production. Early research suggests that taking pyridoxine daily for 6-7 days does not stop breast milk production.

Stroke. Taking pyridoxine by mouth does not seem to prevent the occurrence of another stoke in people with a history of stroke.

Preventing re-blockage of blood vessels after angioplasty. Evidence on the benefits of pyridoxine for preventing the re-blockage of blood vessels after angioplasty is inconsistent. Some evidence suggests that taking folic acid, vitamin B12 and pyridoxine might be beneficial. However, other research finds no benefit.

Asthma. The effectiveness of pyridoxine supplementation in children with asthma is unclear.

Attention deficit-hyperactivity disorder (ADHD). Early research suggests that taking pyridoxine by mouth, with or without high doses of B vitamins, might help ADHD. However, research using high doses of both pyridoxine and vitamins seems to have no effect on ADHD symptoms.

Depression. Early research suggests that taking pyridoxine might reduce depression symptoms in postmenopausal women but not in the general population.

Nerve problems caused by diabetes. Evidence on the effects of pyridoxine in people with nerve problems caused by diabetes is inconsistent. Some research shows that taking pyridoxine with thiamine daily reduces the severity of symptoms, while other research shows no benefit.

Seizures caused by a high fever (febrile seizures). Early research suggests that taking pyridoxine daily for 12 months does not reduce the recurrence of seizures caused by a high fever.

High blood sugar during pregnancy (gestational diabetes). Some early research suggests that taking pyridoxine daily for 2 weeks may lower sugar levels in women with high blood sugar during pregnancy. However other early research shows no benefit of pyridoxine on this condition.

Nerve damage caused by tuberculosis medication. Early research suggests that taking pyridoxine daily might reduce nerve damage caused by a drug taken for tuberculosis.

Complications in pregnancy. Taking pyridoxine during pregnancy does not seem to reduce the risk of eclampsia, pre-eclampsia, or preterm birth, but may reduce the risk of tooth decay.

Nerve damage caused by chemotherapy. Early research suggests that pyridoxine might help reverse nerve damage caused by the chemotherapy drug vincristine.

Boosting the immune system.

Muscle cramps.

Eye problems.

Kidney problems.

Night leg cramps.

Arthritis.

Allergies.

Lyme disease.

Other conditions.

More evidence is needed to rate pyridoxine for these uses.

vitamin b6 Side Effects & Safety

Pyridoxine is LIKELY SAFE for most people when used appropriately.

Pyridoxine is POSSIBLY SAFE when taken by mouth in amounts greater than the recommended dietary allowance. In some people, pyridoxine might cause nausea, vomiting, stomach pain, loss of appetite, headache, tingling, sleepiness, and other side effects.

Long-term use of high doses is POSSIBLY UNSAFE. It might cause certain brain and nerve problems.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Pyridoxine is LIKELY SAFE for pregnant women when taken under the supervision of their healthcare provider. It is sometimes used in pregnancy to control morning sickness. High doses are UNSAFE. High doses can cause newborns to have seizures.

Pyridoxine is LIKELY SAFE for breast-feeding women when used in amounts not larger than 2 mg per day (the recommended dietary allowance). Avoid using higher amounts. Not enough is known about the safety of pyridoxine at higher doses in breast-feeding women.

vitamin b6 Interactions

Amiodarone (Cordarone) might increase your sensitivity to sunlight. Taking vitamin B6 (pyridoxine) along with amiodarone (Cordarone) might increase the chances of sunburn, blistering, or rashes on areas of skin exposed to sunlight. Be sure to wear sunblock and protective clothing when spending time in the sun.

Phenobarbital (Luminal) interacts with PYRIDOXINE (VITAMIN B6)

The body breaks down phenobarbital (Luminal) to get rid of it. Pyridoxine might increase how quickly the body breaks down phenobarbital (Luminal). This could decrease the effectiveness of phenobarbital (Luminal).

Phenytoin (Dilantin) interacts with PYRIDOXINE (VITAMIN B6)

The body breaks down phenytoin (Dilantin) to get rid of it. Pyridoxine (vitamin B6) might increase how quickly the body breaks down phenytoin. Taking pyridoxine (vitamin B6) and taking phenytoin (Dilantin) might decrease the effectiveness of phenytoin (Dilantin) and increase the possibility of seizures. Do not take large doses of pyridoxine (vitamin B6) if you are taking phenytoin (Dilantin).

The body breaks down levodopa to get rid of it. Vitamin B6 (pyridoxine) can increase how quickly the body breaks down and gets rid of levodopa. But this is only a problem if you are taking levodopa alone. Most people take levodopa along with carbidopa (Sinemet). Carbidopa prevents this interaction from occurring. If you are taking levodopa without carbidopa do not take vitamin B6.

vitamin b6 Dosing

The following doses have been studied in scientific research:

BY MOUTH:

For vitamin B6 deficiency in adults: the typical dose is 2.5-25 mg daily for three weeks, then 1.5-2.5 mg per day as maintenance treatment.

For vitamin B6 deficiency in women taking birth control pills: the dose is 25-30 mg per day.

For symptoms of premenstrual syndrome (PMS): the daily dose is 50-100 mg. Doses as high as 500 mg per day have been used, but daily doses over 100 mg don't appear to have additional benefit, and may increase the risk for harmful side effects.

For hereditary sideroblastic anemia: initially 200-600 mg per day is used, decreasing to 30-50 mg daily after improvement.

For kidney stones: 25-500 mg daily has been used.

For treating tardive dyskinesia: 100 mg per day has been increased weekly up to 400 mg per day, given in two divided doses.

For nausea during pregnancy: 10-25 mg pyridoxine three or four times daily has been used; alternatively, 75 mg of sustained-release pyridoxine combined with 12 mcg vitamin B12 (cyanocobalamin), 1 mg folic acid, and 200 mg calcium (PremesisRx) is used daily as an FDA-approved prescription product for nausea during pregnancy.

Clarke, R., Harrison, G., and Richards, S. Effect of vitamins and aspirin on markers of platelet activation, oxidative stress and homocysteine in people at high risk of dementia. J Intern.Med 2003;254(1):67-75. View abstract.

Goodyear-Smith, F. and Arroll, B. What can family physicians offer patients with carpal tunnel syndrome other than surgery? A systematic review of nonsurgical management. Ann.Fam.Med 2004;2(3):267-273. View abstract.

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